org doesn't even make sense as "open source", but pretty much every open source project has a .org domain; and since that's what I do, it works well for me.
I'm treating mine like a pseudo-TLD and just spamming out CNAMEs of @ for pet projects.
Of course, it used to be that an end-user could have the shortest possible domains, just like businesses of "$name.com", but now businesses can drop $25,000/yr on ".$name", which regular people obviously can't. Remains to be seen how much those get used, looks more like everyone wants to buy ".$adjective" gTLDs to resell instead so far.
There are so many new TLDs out there that I couldn't even pick out the real ones from fake ones if you gave me a list. And most of them require no verification whatsoever, so They're completely open to legitimate users and spammers alike.
I dare say it would get you laid at parties. even zuckerberg doesn't have mark.com